Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

907
FXUS63 KLOT 082338
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
538 PM CST Sun Feb 8 2026

.KEY MESSAGES...

- Milder temperatures are expected for much of the upcoming
  work week.

&&

.DISCUSSION...
Issued at 230 PM CST Sun Feb 8 2026

Low-level warm air advection is progged to gradually increase
over the area tonight as a 1002 mb surface low tracks eastward
across southern Manitoba and a secondary surface low attempts to
become better defined south of it. Could see some attempts at
renewed stratus development into tomorrow morning as isentropic
lift helps moisten the 800-950 mb layer, but model guidance as
a whole still suggests that low-level saturation won`t be deep
or widespread enough to support the development of drizzle. Even
the overly-moist NAM has trended lower with its degree of low-
level moisture, so have maintained a dry forecast for tonight
into tomorrow.

Warm air advection at the surface should become more apparent
tomorrow as winds turn southerly. In spite of increasing and
thickening upper-level cloud cover, these southerly winds
should help push temperatures into the 40s across primarily
western portions of our forecast area. Farther to the east
(particularly in areas where a relatively deeper snowpack
remains in place), highs will likely only top out in the mid-
upper 30s.

The cold front associated with the aforementioned low pressure
center(s) will eventually reach northern Illinois tomorrow
night and track across our forecast area from northwest to
southeast during the overnight/early morning hours. A few
models continue to indicate that there is some potential for
drizzle near/along the front. However, the signal for that in
those models does not look all that robust, and with the
majority of forecast guidance still favoring a dry frontal
passage in the absence of better low-level moisture, have
continued to withhold on a formal drizzle mention in the
forecast grids.

While an initial push of cold air advection behind the front
may stunt diurnal warming attempts in the hours just after
sunrise, it nevertheless still appears that the frontal passage
may occur early enough for increasing quantities of sunshine to
push temperatures back into the 40s across a large portion of
our forecast area once again during the afternoon. Northwesterly
winds will then continue into Wednesday, when high temperatures
are expected to be a bit cooler (though still near to above
normal for this time of year). Dry conditions will also persist
for a while longer as surface high pressure builds into the
region late Wednesday into Thursday morning.

Multiple upper-level disturbances are then forecast to track
through the central CONUS during the latter half of the week and
over the weekend. Depending on their exact evolution (and the
location and strength of the aforementioned surface high as it
settles somewhere near or east of our area), our next
opportunities for wintry precipitation may arise -- primarily
focused during the late Thursday-early Friday time frame and
again sometime over the weekend. However, ensemble spread
remains quite vast from Thursday onward, and there are multiple
potential outcomes that keep most or all of the precipitation
west and south of our forecast area over the latter half of the
forecast period. The lower-end chance PoPs offered by the NBM
during the time frame in question thus continue to look
reasonable from this vantage point.

Ogorek

&&

.AVIATION /00Z TAFS THROUGH 06Z TUESDAY/...
Issued at 538 PM CST Sun Feb 8 2026

Key Aviation Messages for the 00Z TAFs:

- Low probability for a period of MVFR ceilings this evening.

Forecast area remains on the western periphery of surface high
pressure centered over the eastern Great Lakes region. This will
continue to provide modest southeast winds for the terminals
tonight into Monday morning. A narrow, 60-80 mile wide band of
VFR stratus was oriented NW-SE across the terminals approaching
sunset and was drifting slowly north. As the trailing edge
continues to lift north, this VFR deck may scatter across the
terminals early this evening. Model guidance (some of which
continues to be handling the current cloud layers poorly) does
maintain moisture in the 5-6 kft layer overnight however, which
may allow for slowing or redevelopment of this scattering and
have elected to maintain a BKN mention at this time. Guidance
also depicts lower level moisture in the MVFR range, though
other than some shallow stratocu spreading northwest into WI off
Lake Michigan, there are not currently any bases below 5 kft
observed in the region. Suspect the potential for MVFR ceiling
development this evening, while perhaps non-zero, is fairly low
and have maintained only a FEW015 mention with this forecast.

A slow-moving surface cold frontal trough will track across the
upper Midwest/Plains on Monday, while high pressure drifts off
to our east. This should support surface winds becoming
southerly around 10 kts by mid-morning. Looks like 180-190
degree directions should prevail through the afternoon for ORD,
with some potential for briefly backing to 170-160-ish Monday
for a time Monday evening.

Ratzer

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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